Peter Schwab

Ruthenium Trichloride, Tricyclohexyl‐ phosphane, 1‐Alkynes, Magnesium, Hydrogen, and Water—Ingredients of an Efficient One‐Pot Synthesis of Ruthenium Catalysts for Olefin Metathesis

An active role is played by MgCl2 during the conversion of the vinylidene precursor 2 into carbenes 3 (R=H, Ph; L=P(C6 H11 )3 ). These complexes can be prepared in a convenient and very efficient one-pot synthesis and have a catalytic activity in metathesis comparable to that of Grubbs compound (Ph instead of CH2 R).

Carbynehydridoruthenium Complexes as Catalysts for the Selective, Ring-Opening Metathesis of Cyclopentene with Methyl Acrylate

The first members of a homologous series of long-chain, multiply unsaturated esters were obtained upon selective ring-opening metathesis of cyclopentene with methyl acrylate [Eq. (a)]. The catalysts are cationic carbynehydridoruthenium complexes (e.g. L=OEt2 ), which were prepared for the first time by protonation of hydridovinylideneruthenium compounds in the presence of L.

RuCl3, P(C6H11)3, 1-Alkine, Mg, H2 und H2O: Komponenten einer effizienten Eintopfsynthese von Ru-Olefinmetathese- Katalysatoren

Eine aktive Rolle spielt MgCl2 bei der Umwandlung der Vinylidenvorstufe 2 in die Carbenkomplexe 3 (R = H, Ph; L = P(C6H11)3). Diese lassen sich durch die Reaktion von 1 mit 1-Alkinen in einer einfachen und sehr effizienten Eintopfsynthese herstellen und weisen bei der Olefinmetathese eine ahnliche Katalyseaktivitat auf wie die von Grubbs entwickelte Verbindung (mit Ph statt CH2R).

Bis(triisopropylarsan) - und Bis(triisopropylstiban)-rhodium(I)-komplexe mit isonitrilen, olefinen, alkinen und diinen als liganden

Abstract The synthesis of a series of monomeric rhodium(I) complexes of general composition trans-[RhCl(L)(AsiPr3)2] and trans-[RhCl(L)(SbiPr3)2] is reported. All compounds are prepared by displacement of the ethene ligand in trans-[RhCl(C2H4)(EiPr3)2] (1: E = As; 2: E = Sb) by isocyanides CNR, α,β-unsaturated carbonyl compounds CH2 = CHC( O)R, alkynes RC = CR′ and diynes RC  CC  CR. The isolated complexes 3–21 have been characterized by elemental analysis, IR and NMR spectroscopy, and in the case of trans-[RhCl(CNMe)(SbiPr3)2] (5) by X-ray crystal structure determination. The bis(triisopropylstibane)rhodium compound 2 reacts with HC  CR (R = Ph, CO2Me, tBu) not to give the expected vinylidene complexes trans-[RhCl( = C = CHR)(SbiPr3)2] but instead catalyzes the formation of the corresponding E-enzynes RCH=CHC  CR. The mechanism of this stereoselective dimerization process will be dicussed.

A series of rhodium(I) complexes, including carbene, vinylidene and allenylidene derivatives, with the bifunctional arsine Pri2AsCH2CH2OMe as ligand

A series of rhodium(I) complexes containing the new bifunctional arsine ligand Pri2AsCH2CH2OMe 1 has been prepared. Most of the compounds were obtained from the ethene derivative trans-{RhCl(C2H4)(Pri2AsCH2CH2OMe)2}5 which was obtained from [{RhCl(C2H4)2}2] and 1 in about 80% yield. The ethene can be displaced by CO, CNBut, CH2CHC(O)Me, CH2CHCO2Me, HCCPh. HCCCO2Me, PhCCSiMe3, MeCCMe, PhCCMe, MeCCCCMe or Me3SiCCCCSiMe3(L) to give the four-co-ordinated rhodium(I) complexes trans-[RhCI(L)(Pri2AsCH2CH2OMe)2] almost quantitatively. The reaction of 5 with H2 affords the dihydride (RhH2Cl(Pri2AsCH2CH2OMe)2 which appears to be fluxional in solution. Photolysis of 5 leads to the elimination of CH2CHOMe and the formation of trans-[RhCl(C2H4)(HAsPri2)2] which is also accessible from 3 and HAsPr12. The vinylidene complexes trans-[RhCl(CCHR)(Pri2AsCH2CH2OMe)2] are obtained either on photochemically induced rearrangement of the isomerie alk-1-yne derivatives (R = Ph or CO2Me) or directly from 5 and HCCR (R = Me or But). The reaction of 5 with a large excess of HCCMe or MeCCBut gives the rhodium(I) allenes trans-[RhCl(CH2CCHR)(Pri2AsCH2CH2OMe)2](R = H or But). The allenylidene compounds trans-[RhCl(CCCRR′)(Pri2AsCH2CH2OMe)2](R = Ph, R′= Ph or C6H4Me-O) are obtained from the functionalized vinylidene derivatives trans-[RhCl(CCHCRR′OH)(Pri2AsCH2CH2OMe)2] upon treatment with Al2O3. From trans-[RhCl(CCCRR′)(Pri2AsCH2CH2OMe)2] and NaC5H5 the half-sandwiches [C5H5Rh(CCCRR′)(Pri2AsCH2CH2OMe)] have been prepared. Compound 5 reacts with N2CPh2 and N2C(C6H4Me-p)2 to yield the carbene complexes trans-[RhCl(CR2)(Pri2AsCH2CH2OMe)2] whereas from 5 and N2CRC(O)Ph (R = H or Ph) the diazoalkane rhodium compounds trans-[RhCl(N2CRC(O)Ph)(Pri2AsCH2CH2OMe)2] are obtained.